Well we all know that git is a great tool for managing your code, but what about if you want to manage git access to your various repos. Welcome to gitolite available under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
"Gitolite allows you to setup git hosting on a central server, with fine-grained access control and many more powerful features." gitolite.com
For help in setting this up I found a useful article that explains a little about how it works here: